Ray WA, Murray KT, Meredith S, et al: Oral erythromycin and the risk of sudden death from cardiac causes. N Eng J Med 2004;351(11):1089-96.
Erythromycin prolongs cardiac repolarization and has been associated with ventricular arrhythmias. Other drugs that are metabolized by the CYP 3A isozymes can increase plasma erythromycin levels.
The authors analyzed data from a Tennessee Medicaid population that included 1,249,943 person-years of follow-up and 1,476 cases of sudden death from cardiac causes. Data regarding current or past use of erythromycin, amoxicillin, and CYP 3A inhibitors were analyzed. The adjusted rate of sudden death from cardiac causes among patients currently using erythromycin was twice as high as among those who had not used erythromycin. The adjusted rate of sudden death from cardiac causes was five times as high among those who concurrently used CYP 3A inhibitors and erythromycin as among those who used neither CYP 3A inhibitors nor erythromycin. There are alternatives to erythromycin and to most CYP 3A inhibitors.